Vietnamese Doan Thi Huong, 29, and Indonesian Siti Aisyah, 25, are accused of rubbing the chemical on his face.

The pair say it was a TV prank and they were tricked by North Korean agents.

Pyongyang has denied any involvement in the killing, but in court prosecutors said that four men - believed to be four North Koreans who fled Malaysia on the day of murder - were also charged in the case.

The incident led to a bitter diplomatic row and strained the once cordial ties between North Korea and Malaysia, which expelled each other's ambassadors.

How is North Korea involved?

The two women, who were arrested days after the killing, have insisted that they were tricked by North Koreans into taking part in what they thought was a TV prank. Four North Korean men who fled Malaysia shortly after the incident are believed to suspects. Interpol issued "red notices" for their arrest in March.

Malaysia has named and questioned other North Koreans in relation to the case.

But authorities also allowed three of them to leave the country in late March, in return for North Korea releasing nine Malaysian diplomats and their families.